SS piety strat is quite difficult on deity, and I could never get it to work. I either miss the buildings, or get reformed too late and lose SS. Even if you manage to get it, getting past the massive cultures of deity ai is a challenge. I think I only seen it done once. About that Songhai map, I went 5 city trad and still got Dow from Liz, pretty crazy neighbors. I was only lucky because my city was easily defensible and she made peace easily.